FORTY-FIRST ANNUAL CONVENTION 153 



Rotation : Corn, Corn, Oats, Wheat, Clover and, in addi- 

 tion, one-tenth of the land in Alfalfa. 













Lbs. N. 



Lbs. N. 













Required. 



Recovered 



I acre 



Corn 



% sold 



Va 



fed 



I GO 



18.75 



I acre 



Corn 



M sold 



Ya 



fed 



IOC 



18.75 



I acre 



Oats 



Yx sold 



Va 



fed 



66 



12.50 



I acre 



Wheat 



All sold 







71 





I acre 



Clover 



All fed 









120.00 



y2 acre 



Alfalfa 

 Total . 



All fed 









150.00 





• • • • 337 



320.00 





Loss . 





. . . 





.... 



17.00 



Now to turn our consideration to the tables, we will first 

 note that under the grain system of farming, only the first rota- 

 tion will maintain the nitrogen. This is the three year rotation 

 of corn, oats and clover. The more common rotation of corn, 

 corn, oats, clover does not even closely maintain nitrogen, and 

 the rotation of corn, oats, wheat and clover, likewise falls far 

 short. For grain system of farming, therefore, we will have 

 to conclude that at least one-third of the cultivated acreage of 

 a farm should be in legumes if the nitrogen is to be permanently 

 maintained. 



The more common, and perhaps more practical, "Mixed 

 System" comprehends that one-half the corn and oats be fed 

 and one-half sold; that all the wheat be sold, and all the clover 

 fed. Here the same three rotations are considered as with the 

 "grain system." 



A summary of the three rotations will reveal the fact that 

 under such a system of farming as this one-third the acreage 

 will a little more than maintain the nitrogen supply, but that 

 one-fourth will not quite maintain the nitrogen. 



Under the "Live Stock System" only two rotations are con- 

 sidered; one three year and one four year, both of which will 

 maintain nitrogen, but^to do this the tables assume perfect 



